As well as elaborating on the ease with which the Catalans signed the Brazilian and praised the player for his humble and unselfish attitude
The 21-year-old joined the Blaugrana for €57.5 million in the summer in Barca's only major move since the end of the 2012-13 season.
Although Madrid were fighting for Neymar's signature in May following a long transfer saga, Barca were the ones to persuade Neymar to leave Santos and Rosell explained that convincing him to come to the club was surprisingly simple.
"I spoke with his father when we met in Miami and we closed the deal there," Rosekk told Cadena SER.
"There were four parties that owned his rights as part of the agreement and we had to agree with all of those, but in the end we closed the deal for €57.5m.
"The key was that the player wanted to come to Barcelona. It was not about knowing how to negotiate; he wanted to be play next to Messi and the rest of the team.
"Everything was based on that despite him having offers from Manchester City, Chelsea, Bayern and Real Madrid.
"Neymar's a very humble, friendly guy, a great team-mate and a great player. He is not selfish on the ball, which is just what we want in a football player. Has has settled perfectly into the squad."